Abstract
We demonstrate exceptional performance for steam electrolysis at intermediate temperatures (500-650 °C) using protonic ceramic electrolyte cells comprised of the proton-permeable, high-activity mixed conductor PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) as the air electrode, the highly proton-conductive and chemically stable perovskite oxide BaZr 0.4 Ce 0.4 Y 0.1 Yb 0.1 O 3 (BZCYYb4411) as the electrolyte, and a composite of Ni-BZCYYb4411 as the fuel electrode. Cells constructed from this material set have been shown previously to function efficiently in fuel cell mode. We demonstrate here reversible operation, enabling hydrogen production when excess electricity is available and immediate electricity generation from stored hydrogen when power demand is high. The cells are stable under cyclic operation and also under prolonged continuous operation in electrolysis mode, undergoing minimal loss in electrochemical characteristics after 500 h at 550 °C. Microstructurally optimized cells yield a remarkable current density of -1.80 A cm -2 at 600 °C and an operating voltage of 1.3 V, of which, based on an electrochemically deduced faradaic efficiency of 76%, -1.37 A cm -2 contributes to useful hydrogen.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 206-215 |
| Number of pages | 10 |
| Journal | Energy and Environmental Science |
| Volume | 12 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2019 |
Funding
This research was funded primarily by the U.S. Department of Energy, through ARPA-e Contract DE-AR0000498, via subcontract from United Technologies Research Center. This work made use of the Cohen X-ray Diffraction Laboratory at North-western University, which has received support from MRSEC program (NSF DMR-1121262) at the Materials Research Center, the Pulsed Laser Deposition facility of Northwestern University, and the EPIC Facility of Northwestern University’s NUANCE Center. These facilities receive support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
ASJC Scopus subject areas
- Environmental Chemistry
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering
- Pollution
